@Espiritus_Corvus, Lusitania’s sinking didn’t have much to do with the US entering the war, since that was, I believe, in 1915, and we didn’t enter the war until 1917. You could say that it was a provocation and a precursor, but definitely not a cause.

The Lusitania most certainly did have much to do with popular support for entering the war. Many moderates who were soft on isolationism, but still against involvement, were turned by this tragedy. Read the frenzied news articles, editorials and letters to the editors of those two years. The Fox News of the day, the influential and popular Hearst Newspapers, tenaciously drove that story to the height of jingoism and kept it in the headlines, riling the unsophisticated masses. Remember, people were not yet aware that the Lusitania was carrying war materiel below decks. In their naive minds this was a most heinous terrorist action against innocent civilians, many of them Americans of leading families—by a nation whose army they were told were cutting the live fetuses out of Belgian women with bayonettes. This, they were told, was the nature of the Hun, and now they were coming after us. Wilson was attacked mercilessly by his own constituency for taking no military action—bravely keeping his campaign promise to not involve the US in a European war. The sinking of the Lusitania wasn’t enough and Wilson held fast, but it is considered by many historians as being a main contributing factor in getting popular support for entry into the war. Even the Kaiser’s advisers complained that it was a huge mistake, after the fact.

Excuse me, it’s late. Wilson didn’t promise to keep us out of war in his first campaign, that was the second campaign in 1916. He did, however, refuse vociferously to involve us after German mobilization in August, 1914 and kept that promise during the Lusitania frenzy, at great loss to his popularity. It was the resumption of unrestricted submarine warfare, a policy which Germany abandoned after the Lusitania fiasco, that finally brought us into the war. The effect of the Lusitania incident upon the German policy of unrestricted submarine warfare, and America’s perception of Germany’s insincerity to respect American neutrality after resumption of same, supports the opinion that the sinking of the Lusitania had much to do with our entry into the war. This distrust of Germany’s claims to respect our neutrality was exacerbated by the Zimmerman telegram that appeared to recruit Mexico as an aggressor against the US from our soft underbelly.